BACKGROUND/AIMS: Although several studies have claimed that Helicobacter pylori (H. pylori) infection is related to cardiovascular disease, it is still uncertain whether it is related to the acute process or the chronic inflammatory atherosclerotic changes. The aim of our study was to confirm the impact of active H. pylori infection on coronary heart disease, acute inflammatory factors, and the coagulation factors. METHODS: A total of 94 patients completed questionnaires about occupation, smoking, past medical history, and socio-economic status. The serum of the subjects was drawn for a low density lipoprotein test, white blood cell count, C reactive protein, fibrinogen, homocysteine, prothrombin time, activated partial thrombin time, plasminogen activator inhibitor type-1, and tissue-type plasminogen test. All of the subjects underwent a coronary angiography and an upper gastrointestinal endoscopy for the diagnosis of coronary heart disease and H. pylori infection, respectively. RESULTS: There was no significant difference in acute inflammatory factors, coagulation factors, atheromatous burden score, and Jeopardy score between the H. pylori-infected group and non-infected group. Odds ratio of H. pylori infection on coronary heart disease was 2.59 (95% CI, 0.80-6.17), but it diminished below 1.0 (95% CI, 0.14-1.36) after adjusting for conventional risk factors such as age, gender, diabetes, hypertension, smoking, body mass index and socio-economic status. CONCLUSIONS: H. pylori infection is not an independent risk factor for coronary heart disease, and it does not alter the coagulation system or evoke the systemic inflammatory response.